Automotive vapor fuel control



May 5, 1959 c. QUINBY AUTOMOTIVE VAPOR FUEL CONTROL Filed Jan. 28, 1957 INVENTOR.

CHARLES E. QUINBY 'ATTORNE/YS United States Patent AUTOMOTIVE VAPOR FUEL CONTROL Charles E. Quinby, Oak Park, Mic h., assignor to Holley Carburetor Company, Van Dyke, MiclL, a corporation of Michigan App ic t n anua y 1 57, S r a No- 6, 1

13 Claims. Cl. 123-133 The present invention relates to automotive vapor fuel control.

It is an object of the present invention to provide in an automotive vehicle a fuel supply system including a chamber in which fuel is vaporized by heat, an air supply passage leading to a cylinder of an internal combustion engine and including a venturi, a fuel supply passage connecting the vaporizing chamber and venturi, and means responsive to one or more variable engine conditions for regulating the pressure of fuel vapor in the chamber.

More specifically, it is an object of the present invention to provide a system as described in the preceding paragraph in which the pressure of vapor in the chamber is regulated by a controlled bleed-E of vapor.

It is a further object of the present invention to provide a system for supplying vaporized fuel to an internal combustion engine including a fuel vaporizing chamber,

a fuel tank, a pump for supplying fuel from the tank to the chamber, a bleed passage connecting the chamber and tank, valve means responsive to one or more variable engine conditions for regulating the bleed-off of fuel vapor to. control the pressure of fuel vapor in the chamher.

It is a further object of the present invention to, provide a system as described in the preceding paragraph including valve means under the control of the operator eifective to move toward closed position to reduce bleed-v off of vapor from the chamber during acceleration to increase vapor pressure at such time.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawing, illustrating a preferred embodiment of the invention, wherein the, figure is a diagrammatic drawing of the system.

The system as disclosed herein supplies fuel vapor to a venturi located in an air intake line adjacent the intake valve of the cylinder. It will be appreciated that the invention need not be so limited and instead, may supply fuel vapor to a venturi located in an air supply passage leading to a manifold which supplies a fuel-air mixture to a plurality of cylinders.

Referring now to the drawing, the system comprises a fuel tank 10, a fuel pump 12 adapted to supply fuel in liquid state to a vaporizing chamber 14. Specifically,

the pump delivers liquid fuel to. a smaller chamber 16 containing a float controlled valve 18 to maintain a constant supply of liquid fuel available for vaporization in the chamber 14. A relief valve 20 is provided to limit the pressure attained in the vaporizing chamber.

Liquid fuel entering the vaporizing chamber 14 is vaporized by a heat source indicated at 22. The heat source may comprise an electrical heating element 22a operable during starting of the engine for vaporizing the fuel and may also include heating means receiving heat as an incident to engine operation such for example as means heated by exhaust gases or the like circulated through conduit 2212.

An engine fuel supply passage 24 connects the vaporizing chamber with each of the venturis 26 which are located in air supply passages 28 leading to separate engine cylinders, or alternatively, to a manifold in communication with a plurality of cylinders. The passage 24. is provided with a restrict-ion 30 and the flow of vaporized fuel to the air induction passage 28 is thus determined by the elevated pressure maintained within the chamber 14, the sub-atmospheric pressure existing in the throat of the venturi upstream of the throttle plate 31, and the effectiveness of the fixed restriction 30.

The pressure of vaporized fuel within the chamber 14 is regulated by a bleed-01f through a bleed passage 32 communicating with branch passages 34 and 36 both of which communicate with the conduit 38 which in turn connects tothe fuel tank 10. The branch passages 34 and 36 contain regulating valves therein under the control of variable engine conditions. As for example, the passage 3.4. is illustrated as having a regulating valve 40 controlled by a thermostat diagrammatically indicated at 42 and operable to control the opening of the valve 40 in accordance with engine operating temperature. The passage 34 also contains a flow restriction 44. The branch passage 36, having a flow restriction 46, also in cludes a regulating valve 48 operatively connected to means responsive to engine load (manifold vacuum), engine speed (venturi depression or both). This means may comprise an evacuated bellows 50 and a bellows 52 connected by a conduit 54 to a source of reduced pressure, as determined by load (manifold vacuum), speed (venturi depression), or a combination of load and speed as shown. The conduit 54 communicates with branch 54a leading to the throat of the venturi and with branch 54b connected to the passage 28 downstream of throttle 31. Branch 54a measures reduced pressure at the throat of the venturi, this pressure being variable and dependent on speed. Branch 54b, on the other hand, is subjected to manifold vacuum or load.

Preferably, the bleed passage 32 is provided with an acceleration lock-out valve 56 which is in series with both of the valves 40 and 4 8 The acceleration lockout valve 56 is under control of the operator and may be completely or partially closed to provide a quick increase pressure of the fuel vapor during acceleration. It will be observed that vapor pressure is in general maintained at a relatively constant elevated value through the operation of the regulating valves 40 and 48 and that accordingly, the continuous vaporization of fuel in the chamber 14, will result in a continuous return of fuel vapor at an elevated temperature to the fuel tank. This results in preheating fuel in the tank.

It will further be observed that with the pressure of vaporized; fuel within the chamber 14 maintained at a substantially constant value dependent on conditions, the instantaneous change in they rate of the flow of fuel s d pend nt Prima ly changes i p e u existing within the throat of the venturi, or in other words, on

engine speed. The system thus provides for an increase in supply of fuel which takes place automatically upon an increase in the supply of air to the cylinder or engine.

The drawing and the foregoing specification constitute a description of the improved automotive vapor fuel control in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

1. A fuel supply system for an internal combustion engine having an air induction passage provided with a venturi, a fuel vaporizing chamber having a heat source associated therewith, a passage connecting said chamber and the throat of said venturi to supply fuel vapor to the air passing through said venturi, bleed passage means for regulating the escape of vapor from said chamber, and regulating means for said bleed passage means comprising valve means responsive to variations in pressure in said air induction passage for controlling flow of fuel vapor through said bleed passage means.

2. A fuel supply system for an internal combustion engine having an air induction passage provided with a venturi, a fuel vaporizing chamber having a heat source associated therewith, a passage connecting said chamber and the throat of said venturi to supply fuel vapor to the air passing through said venturi, bleed passage means for regulating the escape of vapor from said chamber, and regulating means for said bleed passage means comprising valve means responsive to engine temperature for controlling flow of fuel vapor through said bleed passage means.

3. A fuel supply system for an internal combustion engine having an air induction passage provided with a venturi, a fuel vaporizing chamber having a heat source associated therewith, a passage connecting said chamber and the throat of said venturi to supply fuel vapor to the air passing through said venturi, bleed passage means for regulating the escape of vapor from said chamber, and regulating means for said bleed passage means comprising valve means responsive to engine load for controlling flow of fuel vapor through said bleed passage means.

4. A fuel supply system for an internal combustion engine having an air induction passage provided with a venturi, a fuel vaporizing chamber having a heat source associated therewith, a passage connecting said chamber and the throat of said venturi to supply fuel vapor to the air passing through said venturi, bleed passage means for regulating the escape of vapor from said chamber, and regulating means for said bleed passage means comprising valve means responsive to both engine temperature and load for controlling flow of fuel vapor through said bleed passage means.

5. A fuel supply system for an internal combustion engine having an air induction passage provided with a venturi, a fuel vaporizing chamber having a heat source associated therewith, a passage connecting said chamber and the throat of said venturi to supply fuel vapor to the air passing through said venturi, bleed passage means for regulating the escape of vapor from said chamber, regulating means for said bleed passage means comprising valve means responsive to variations in pressure in said air induction passage for controlling flow of fuel vapor through said bleed passage means, and means under the control of the operator for restricting flow through said bleed passage means when rapid acceleration is required.

6. A fuel supply system for an internal combustion engine having an air induction passage provided with a venturi, a fuel vaporizing chamber having a heat source associated therewith, a passage connecting said chamber and the throat of said venturi to supply fuel vapor to the air passing through said venturi, a bleed passage having a normally open valve under the control of the operator adapted to be closed to restrict flow when rapid acceleration is required.

7. A fuel supply system for an internal combustion engine having an air induction passage provided with a venturi, a fuel vaporizing chamber having a heat source associated therewith, a passage connecting said chamber and the throat of said venturi to supply fuel vapor to the air passing through said venturi, a bleed passage having a normally open valve under the control of the operator adapted to be closed to restrict flow when rapid acceleration is required, and a second valve in series with said normally open valve operated in response to variations in pressure in said air induction passage to regulate vapor pressure within said chamber.

8. A fuel supply system for an internal combustion engine having an air induction passage provided with a venturi, a fuel vaporizing chamber having a heat source associated therewith, a passage connecting said chamber and the throat of said venturi to supply fuel vapor to the air passing through said venturi, a bleed passage having a normally open valve under the control of the operator adapted to be closed to restrict flow when rapid acceleration is required, and a second valve in series with said normally open valve operated in response to engine temperature to regulate vapor pressure within said chamber.

9. A fuel supply system for an internal combustion engine having an air induction passage provided with a venturi, a fuel vaporizing chamber having a heat source associated therewith, a passage connecting said chamber and the throat of said venturi to supply fuel vapor to the air passing through said venturi, a bleed passage having a normally open valve under the control of the operator adapted to be closed to restrict flow when rapid acceleration is required, and a second valve in series with said normally open valve operated in response to engine load to regulate vapor pressure within said chamber.

10. A fuel supply system for an internal combustion engine having an air induction passage provided with a venturi, a fuel vaporizing chamber having a heat source associated therewith, a passage connecting said chamber and the throat of said venturi to supply fuel vapor to the air passing through said venturi, a bleed passage having a normally open valve under the control of the operator adapted to be closed to restrict flow when rapid accelerat-ion is required, parallel branch passages connected to said bleed passage, and regulating valves responsive respectively to engine temperature and load in said branch passages.

11. A fuel supply system for an internal combustion engine having a plurality of cylinders, an air induction passage leading to each cylinder, a venturi in each induction passage, a fuel tank, a fuel vaporizing chamber, means for supplying fuel from said tank to said chamber, a heater for said chamber to vaporize fuel therein and to maintain fuel vapor at an elevated pressure, bleed passage means including parallel branches, regulating valves in said branches responsive respectively to engine temperature and load, a valve under the control of the operator in series with both of said regulating valves adapted to be moved toward closed position to increase vapor pressure in said chamber for acceleration, said bleed passage means extending to said tank to return bled vapors thereto.

12. A fuel supply system for an internal combustion engine having an air induction passage provided with a venturi, a fuel tank, a fuel vaporizing chamber, means for supplying fuel from said tank to said chamber, a heater for said chamber to vaporize fuel therein and to maintain fuel vapor at an elevated pressure, bleed passage means including parallel branches, regulating valves in said branches responsive respectively to engine temperature and load, a valve under the control of the operator in series with both of said regulating valves adapted to be moved toward closed position to increase vapor pressure in said chamber for acceleration, said bleed passage means extending to said tank to return bled vapors 5 thereto, and a vapor passage connecting said chamber to said venturi.

13. A fuel system for an internal combustion engine having an air intake passage comprising a liquid fuel tank, a fuel vaporizing chamber, means for moving liquid fuel from said tank to said chamber, a heat source associated with said chamber to vaporize liquid fuel therein, a passage connecting said vaporizing chamber to said air intake passage, bleed passage means connecting said vatank, and valve means in said bleed passage means to control vapor pressure in said vaporizing chamber.

References Cited in the file of this patent porizing chamber to said tank to return vapors to said 10 2,731,801

UNITED STATES PATENTS Crain Sept. 11, 1928 Ensign July 8, 1941 Spanjer June 28, 1955 Reed Jan. 24, 1956 

